Logo
FULL SITE MENU

Engine replacement50L to 57L %3dless power amp speed %3d major problem Why

S

scubaman

Member
I just finished replacing a 5.

I just finished replacing a 5.0L(500A) Volvo with a new 5.7L Indmar engine with a 4bbl holley. My old engine was 190 hp (cracked block) and the new one is 315hp at the crank. The outdrive is a volvo DP. I expected great results but got less power and about half the speed. Where is the problem? I have a volvo outdrive (less than 100 hrs(mint) DP. Both engine company and volvo said I didn't need to make any changes in my setup. The motor also has to be choked every time. Cannot start without choking even when warmed up. Ther linkage appears to move the full distance? Feels like half power. Gas is all fresh. (note) plug with wire near top front of intake manifold with wire going no where. no placed to hook up? HELP!! Any ideas??? Thanks
 
"Is the carb well set? It coul

"Is the carb well set? It could be that the secondaries are not opening or the choke is not releasing. Also, the intake manifold could be getting air somewhere other that from the carb. Is there a fitting for a vacuum gauge in the intake manifold that may have been left unplugged?

Regarding the wire and plug, could you upload a picture?

Also, you may want to contact Indmar, they may have the answer."
 
You have some major fuel deliv

You have some major fuel delivery problems that need to be worked out. Have the fuel filters/ separators been changed recently?

Jeff
 
"Thanks for the picture, John.

"Thanks for the picture, John. I am wondering if that extra wire is supposed to go to a "coolant temperature alarm" sensor. I have difficulty distinguishing the colour, but in the picture it looks the same colour as the one going to the water temperature sender.


Regarding our engine's lack of performance, I assume your Holley has an electric choke. Make sure there is a wire (supposedly purple) going to one of the connectors and a black one going to the other one. You should have 12 V between both of them when the engine is running. And if you have an electric choke, make sure it is working and properly adjusted so that it is fully opened after the engine has been running for a little while (you will have to remove the flame arrestor to see this).

Also, noticed in your picture that the red wire seems to be partially cut?

Something else you may want to check is that the spark plug wires are connected according to the correct firing order. If your engine is standard rotation, the firing order should be 1-8-4-3-6-5-7-2.

81852.jpg
"
 
"Thanks for all the help. I a

"Thanks for all the help. I am not so sure that my local repair shop is up to date. I think he did the switch and did not time it. I bet the timing shunt is still in. The sensor in the pix is the oil pressure unit. One wire is free. I will check out the red one.
Besides the timing, my hp will jump from 190 to 295hp or so. I was told the props do not need changing. I currently use the dual prop. Is this okay?? Thanks"
 
"John, the sensor in the pic s

"John, the sensor in the pic seems to me the water temperature sender. I am not aware of any oil being in the intake manifold area, unless I have missed something major."
 
[b]"I expected great resul

"I expected great results but got less power and about half the speed. Where is the problem? The motor also has to be choked every time. Cannot start without choking even when warmed up."

That sounds like a Serious Fuel Delivery Issue to Me...........
 
"So far no luck. My mechanic&

"So far no luck. My mechanic(?) still hasn't found the problem. Not much choice for boat engine service here in central PA. Might pick up boat and do my own service. Can a auto mechanic recheck the timing on my 5.7 Indmar?(of course with water hook up) The throttle linkage has full range of movement. I replaced all the fuel which was old. Can a dirty fuel filter and old gas cause the problem with choking the engine every time(priming the fuel in start position? The engine acts like it isn't getting. fuel to start without priming and choking. Also,is a propellar change necessary. The RPM was about 1/2 or slightly more. a lot lower than normal. I have the duoprop. Changed from 5.0L to 5.7l, 190hp to 300hp? HELP. Thanks"
 
Someone in the forum had a sim

Someone in the forum had a similar problem and found the anti-siphon valve in the fuel line jammed. How is yours?

You can also try hooking a jerrycan with fresh gas to the fuel pump suction side and see what happens.
 
"Thanks El Pescador! There is

"Thanks El Pescador! There is a vaccum ,fitting behind the automatic choke which is open and not plugged. Should this be plugged? Also, I could not find an in line fuel filter. There is a different kind of water separation filter located where the old used to be. Bottom Left as you face the engine. It is smaller and has a few wires attached on the bottom which lead to the carb or distributor(bundle shown in old picture with engine tem sensor. Is this a new style fuel/water filter or maybe the fuel pump? The fuel line leads to this from the tank and exits to the carb. It is located exactly where the old spin on water separator was. Thanks"
 
"El Pescador, If you get time,

"El Pescador, If you get time, could you view my engine on ebay. It is listed as 5.7L engine Gold package. It shows several pictures of the engine. Is the water separation filter or a fuel pump on the lower left front as you face it? Thanks What threw me off was the wires connected to it."
 
"That's the engine's e

"That's the engine's electric fuel pump, so I hope you have it connected. Also, the hose behind the automatic choke is the a vent coming from the head so that the blowby gases from the crankcase are sucked again into the intake manifold."
 
"Many thanks, Where is the fu

"Many thanks, Where is the fuel filter and water separation filter? The fuel pump is in the exact location as my old water separation filter. There is nothing between the fuel tank and fuel pump but fuel line. Thanks again"
 
"Some engine arrangements do n

"Some engine arrangements do not come with a fuel filter/water separator, and you have to install one yourself (they are cheap enough anyway)."
 
"Problem apparently solved. S

"Problem apparently solved. Some other new engines from same company have major problem with secondary jets in Holley Carbs. Will be replaced with another Holley. My family has had some family history with Holley Auto Carbs. When they work, they are great. When they don't they can test you. Wish I could afford to get another brand such as edelbrock. Thanks"
 
Back
Top